摘要:
A process for the preparation of 5-(3,5-dimethylphenoxymethyl)-2-oxazolidinone, which includes: a) reacting 3,5-dimethylphonel with epichlorohydrin to obtain a mixture of 1-(3,5-dimethylphenoxy)2,3-epoxy propane (1) and 1-(3,5-dimethylphenoxy)-3-chloro-2-propanol (2); b) reacting the mixture of (1) and (2) obtained from step (a) with benzylamine to obtain a first compound; c) reducing the first compound with hydrogen in presence of ammonia, to obtain a second compound; and d) reacting the second compound with dimethylcarbonate in the presence of a strong base to obtain 5-(3,5-dimethlphenoxymethyl)-2-oxazolidinone.
摘要:
In a process for the preparation of 4,5-diphenyloxazole-2-propanoic acid, the improvement consisting in using toluene in the esterification reaction of benzoin, and acetic acid/formic acid in the subsequent cyclization, thereby obtaining higher yields and avoiding the use and the disposal of high amounts of pyridine.
摘要:
Gabapentin free from mineral acids anions is obtained by precipitating from a gabapentin aqueous solution a corresponding hydroxybenzoate, from which pure gabapentin is subsequently obtained by dissolution in a lower alcohol and treatment with a tertiary base.
摘要:
Pure gabapentin form II can be directly obtained adding the solution of the corresponding hydrochloride in dry ethanol (from which the inorganic salts have been filtered off) with a tertiary amine and a small amount of water.
摘要:
Naproxene ((+)-6-methoxy-.alpha.-methyl-2-naphthaleneacetic acid) is recovered from the corresponding racemic acid by treatment of the latter with N-substituted R-(-)-2-amino-1-butanols and recovery of the resulting diastereomeric salt.